Browse Prior Art Database

TN3270 Current Practices (RFC1576)

IP.com Disclosure Number: IPCOM000002410D
Original Publication Date: 1994-Jan-01
Included in the Prior Art Database: 2000-Sep-12
Document File: 10 page(s) / 23K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Penner: AUTHOR

Abstract

This document describes the existing implementation of transferring 3270 display terminal data using currently available telnet capabilities. The name traditionally associated with this implementation is TN3270.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 12% of the total text.

Network Working Group J. Penner

Request for Comments: 1576 DCA, Inc.

Category: Informational January 1994

TN3270 Current Practices

Status of this Memo

This memo provides information for the Internet community. This memo

does not specify an Internet standard of any kind. Distribution of

this memo is unlimited.

Abstract

This document describes the existing implementation of transferring

3270 display terminal data using currently available telnet

capabilities. The name traditionally associated with this

implementation is TN3270.

Information is provided to aid in the implementation of TN3270

servers as well as client terminal emulators.

The following areas pertaining to TN3270 implementations are covered

in this document:

1. the telnet options negotiated to transition from a NVT ASCII

state to a TN3270 state ready to process incoming 3270 data

stream commands

2. the method for sending and receiving 3270 data

3. the method of handling some special keys known as SYSREQ and

ATTN using current available telnet commands

4. the events that will transition a TN3270 session back to an NVT

session

Table of Contents

1. Motivation . . . . . . . . . . . . . . . . . . . 2

2. Background . . . . . . . . . . . . . . . . . . . 2

3. Telnet Options and Commands Used . . . . . . . . 4

4. Connection Negotiation . . . . . . . . . . . . . 4

4.1 3270 Regime Option . . . . . . . . . . . . . . . 6

4.2 Suppress Go Ahead Option . . . . . . . . . . . . 6

4.3 Echo Option . . . . . . . . . . . . . . . . . . . 6

4.4 Timing Mark Option . . . . . . . . . . . . . . . 7

5. Testing for session presence . . . . . . . . . . 7

6. Handling 3270 data . . . . . . . . . . . . . . . 7

7. 3270 Structured Fields . . . . . . . . . . . . . 8

8. The 3270 ATTN (Attention) Key . . . . . . . . . . 8

9. The 3270 SYSREQ Key . . . . . . . . . . . . . . . 9

10. Items not addressed by TN3270 . . . . . . . . . . 10

11. References . . . . . . . . . . . . . . . . . . . 10

12. Security Considerations . . . . . . . . . . . . . 11

13. Author's Note . . . . . . . . . . . . . . . . . . 11

14. Author's Address . . . . . . . . . . . . . . . . 12

1. Motivation

3270 display terminal data differs from traditional display terminal

data in that it is block mode and uses EBCDIC instead of ASCII

character represen...